RREB1 repressed miR-143/145 modulates KRAS signaling through downregulation of multiple targets.
Oncogene
; 32(20): 2576-85, 2013 May 16.
Article
de En
| MEDLINE
| ID: mdl-22751122
ABSTRACT
A lack of expression of miR-143 and miR-145 has been demonstrated to be a frequent feature of colorectal tumors. Activating KRAS mutations have been reported in 30-60% of colorectal cancers and an inverse correlation between Kras and miR-143/145 expression has been observed. Previously, we have demonstrated that oncogenic Kras leads to repression of the miR-143/145 cluster in pancreatic cancer and is dependent on the Ras responsive element (RRE) binding protein (RREB1), which negatively regulates miR-143/145 expression. In the present study, we have found that RREB1 is overexpressed in colorectal adenocarcinoma tumors and cell lines, and the expression of the miR-143/145 primary transcript is inversely related to RREB1 expression. In colorectal cancer cell lines, the miR-143/145 cluster is repressed by RREB1 downstream of constitutively active KRAS. RREB1 is activated by the MAPK pathway and negatively represses the miR-143/145 promoter through interaction with two RREs. In addition, overexpression of miR-143 or miR-145 in HCT116 cells abrogates signaling through the MAPK, PI3K and JNK pathways by downregulation of both KRAS and RREB1 in addition to downregulation of a cohort of genes in the MAPK signaling cascade. These results establish a complex network of regulation through which the miR-143/145 cluster is able to modulate KRAS signaling in colorectal cancer.
Texte intégral:
1
Collection:
01-internacional
Base de données:
MEDLINE
Sujet principal:
Facteurs de transcription
/
Régulation de l'expression des gènes tumoraux
/
Protéines G ras
/
MicroARN
/
Protéines de liaison à l'ADN
Limites:
Humans
Langue:
En
Journal:
Oncogene
Sujet du journal:
BIOLOGIA MOLECULAR
/
NEOPLASIAS
Année:
2013
Type de document:
Article
Pays d'affiliation:
États-Unis d'Amérique